.NET Framework 4 RTM Migration Issues on MSDN

.NET Framework 4 RTM became available for download alongside Visual Studio 2010 RTM the past week, with Microsoft topping the releases off with Silverlight 4 RTW. Additional resources to accompany the development platform and tools are also served by Microsoft, most of them free of charge, in order to streamline software-building efforts. It is the case of the .NET Framework 4 Migration Issues documentation published on MSDN last week. As the name implies, the resources are focused on detailing problems and breaking changes that developers can come across when adapting their projects to the latest iteration of .NET Framework.

“With the release of .NET Framework 4 last week, it is relevant to talk about migration issues you might run into when upgrading your applications to .NET 4. My team has put together a topic that describes the migration issues (formerly known as breaking changes) between the .NET Framework version 3.5 Service Pack 1 and the .NET Framework version 4. The change in terminology is to reflect the fact that not all changes introduced by a new version of the framework break your application; rather, these are changes in behavior discovered during design review and testing that could potentially impact an application,” Maira Wenzel, documentation manager for the CLR User Education team at Microsoft, explained

Developers will be able to access detailed information on breaking changes in .NET Framework 4 areas such as ASP.NET, Core, Data (ADO.NET), Windows Communication Foundation (WCF), Windows Presentation Foundation (WPF) and XML. The MSDN resource includes migration issues for new .NET Framework fixes, evolved standards compliance and security, but also additional enhancements generated by customer feedback. Most importantly, the Redmond company is also offering guidance for the breaking changes that require programming modifications to be applied to applications. Some of the migration issues include the following:

1. ASP.NET Issues
   1. Browser definition files
   2. Child applications running under mixed versions of ASP.NET
   3. ClientID changes
   4. Code access security (CAS)
   5. Configuration files
   6. Control rendering
   7. Event handlers in default documents
   8. Hashing algorithm
   9. HtmlEncode and UrlEncode methods
   10. HttpException errors in ASP.NET 2.0 applications
   11. Membership types
   12. Menu control changes
   13. Mobile assembly in Web.config file
   14. Output caching
   15. Page parsing
   16. Passport types
   17. PathInfo information in the FilePath property
   18. Request validation
   19. Routing
   20. SharePoint sites
   21. XHTML 1.1 standards
2. Core Issues
   1. Configuration files
   2. Hosting – (unmanaged API)
   3. New security model
3. Date and Time Issues
   1. Daylight savings
   2. Formatting strings
4. Globalization Issues
   1. Culture names
   2. LCID parameter
   3. Obsolete culture types
   4. Retrieving culture
   5. Unicode 5.1 standards
5. Exceptions Issues
   1. Exceptions for corrupted process state
   2. Execution engine exceptions
6. Reflection Issues
   1. Assembly hash algorithms
   2. Assembly loading
   3. Declaring type
   4. Delegates
   5. Global assembly cache location change
7. Interoperability Issues
   1. Buffer length – (unmanaged API)
   2. JIT debugging
   3. Platform invoke
   4. Removed interfaces – (unmanaged API)